MRCP UK EXAMINATIONS

Detailed explanation-1: -An individual must inherit two non-functioning CF genes – one from each parent – to have CF. If both parents are carriers there is a 1 in 4 (25 percent) chance that both will pass on the non-functioning gene, which would result in a pregnancy affected with cystic fibrosis.

Detailed explanation-2: -If both parents, are carriers for CF, a future child could get two mutations, (C) one from each parent and therefore have cystic fibrosis. When both parents are carriers (CN), every baby has 25% chance of having cystic fibrosis.

Detailed explanation-3: -Cystic fibrosis (CF) is a genetic disease. This means that CF is inherited. A child will be born with CF only if two CF genes are inherited-one from the mother and one from the father. A person who has only one CF gene is healthy and said to be a “carrier” of the disease.

Detailed explanation-4: -The gene that causes cystic fibrosis is recessive. This means that in order to have cystic fibrosis, children must inherit two copies of the gene, one from each parent. If a child inherits only one copy, he or she won’t develop cystic fibrosis.

Detailed explanation-5: -A person must inherit two CF genes to have CF disease. When your child was conceived, * he or she received a CF gene from both you and your partner. A child can inherit CF only if both parents carry a CF gene (that is, each parent either has CF or is a carrier*) and both parents pass the CF gene on to their child.